BRACK YITRA. 



373 



ALOOCK describes. There is a difference between the sexes in rostral length. Thus 

 the measurements show that for 6 males the mean value of K.I. -j-0.1. = 0*41, and 

 range of variation = 0*36-0 '45. For 10 females the corresponding figures are 0'32 

 and 0'29-0'33. Neither the slight variation among the female nor the considerable 

 variation among the male specimens seems to be particularly associated with growth. 



Simocarcinus simplex (DANA), 1852, var. pyramidatus, nov. A.l. p. 190. 



[Huenia hellerii, PAULSON, 'Crustacea of the Red Sea' (Russian), Kiev, 1875, p. H, pi. iii., 

 figs. 2a to c.] Trigonothir pyramidatus, KLUNZINGER, p. 19, pi. i., figs. 3 to 3g. 



Localities : Jokkenpiddi Paar, three specimens (a, b, d) ; south end of Cheval Paar, 

 one specimen (e) ; coral reefs, Gulf of Manaar, one specimen (/) ; pearl banks, Gulf 

 of Manaar, four specimens (g, h, i, j) ; off Mutwal Island, one specimen (c). 



Description : 



C.I 



RL-5-G1 0-95 



C.b.-rC.l 0-86 



Inter-orb.b. -rC.l. . 



Ch.l.^C.1 1-97 



W.L.1.L-S-C.1. . . 

 W.L.2.1.-7-C.L . . 

 W.L.4.L-5-C.L . . 



All the specimens have three tubercles on the gastric region of the carapace ; they 

 are somewhat blunter in the female than in the male. 



The rostrum exhibits variability in several respects : (1) In its length, as above ; 

 (2) it may be straight or curved, in the latter case the concavity is below ; (3) it may 

 arise from the front of the carapace in such a way as to continue the general 

 horizontal plane of the dorsal surface of the carapace, or it may rise upwards some- 

 what and make an obtuse angle with that plane. In one male the rostrum is 

 straight and its plane horizontal ; in two males it is curved and makes an obtuse 

 angle with the post-rostral carapace. 



The hands of one male are massive, with fingers which are only apposable at their 

 tips, and which are, when so apposed, separated at the base by a considerable space ; 

 in two other males the hands are slender and the fingers when apposed distally are 

 almost in contact basally. 



A lobe is present in ail the specimens on either side of the posterior border of the 

 carapace. The size of the lobes is intermediate between those of dried specimens of 

 S. simplex in the British Museum and HELLER'S figure of pyramidatiis. 



The eye is much as in the British Museum specimens of simplex, i.e., less prominent 

 than in DANA'S figure. In each of the three females which I place with the above 

 males there is a pair of hepatic lobes. 



